South Dakota School of Manes 79 



of Pliocene time.' It is of interest to note in this connection 

 that the nearest living allies of the Black Hills Oligocene and 

 Miocene forms are certain foxes now inhabiting South America. 

 According to Cope, the Canidae, so far as concerns struc- 

 ture, occupy a position intermediate between the generalized 

 carnivores, such as the raccoons, and the highest specialized 

 forms, the cats ; but in brain character they display superiority 

 to all of the other carnivore families. The chief differences 

 between the Tertiary and the living forms lie in the higher 

 specialization of the latter, particularly as regards foot struc- 

 ture and brain character. 



The Canidae seem almost certainly to have descended di- 

 rectly from the early Eocene Creodonta, but so undoubtedly did 

 the Felidae. During the Oligocene time the two families were 

 much generalized and had many characters in common, partic- 

 ularly in the dentition, the structure of the skull, the vertebrae, 

 the limbs, and the feet. One feature of surprising interest, 

 first indicated by Prof. Scott, is that some at least of the Canidae 

 had sharp pointed, high, compressed, hooded claws, as in the 

 cats, instead of curved, cylindrical cones, as in the dogs, and had 

 the unmistakable ability of retracting the claws to a greater or 

 less extent. 



Although many specimens of the Canidae have been found 

 in the bad land formations of the Black Hills region, few com- 

 plete skeletons have been obtained. Until recent years little had 

 been collected but heads. Partly on account of the rarity of 

 complete skeletons and partly on account of inherent difficulties 

 in the nature of the species the * phylogenetic history of the 

 various families has not been very satisfactorily worked out 

 The following species are represented : 

 Lower Oligocene. 



Daphoenus dodgei, Scott t 



Middle Oligocene. 



Daphoenus vetus, Leidy. 

 Daphoenus hartshamianus (Cope). 

 Daphoenus felinus, Scott. 

 Daphoenus nebrascensis (Hatcher.) 

 Daphoenus in flatus (Hatcher.) 

 Cynodictis gregarius (Cope.) 

 Cynodictis lip pine ottianus (Cope.) 

 Upper Oligocene. 



Cynodictis tcmnodon, Wortman and Matthew. 



